The president also stated that Muslims make up the group most often victimized by the minority of extremists within the Muslim population. We found some data in the Pew Research poll we used in last week’s fact that may help shed some light on the frequent victimization of their fellow Muslims by the extremist minority.

Pew Research examined the degree to which Muslims agree that a person who leaves the Muslim religion deserves capital punishment. The percentage of Muslims, that is, who believe a person who leaves Islam deserves the death penalty. But Pew somewhat buried the data by expressing the percentage in relation to the number of Muslims who think their national government should pattern itself on Muslim sharia law. That method of counting makes it easy for readers to misinterpret the data and exaggerate the numbers.

But the numbers are shocking even accounting for Pew’s method of presentation. We took the percentage of Muslims favoring sharia and ran the numbers to come up with a chart that tells the story clearly.

Update and Correction, Feb. 23, 2015: An anonymous blogger at the “Empethop” website pointed out to us that Pew did ask general populations of Muslims about the death penalty for apostasy. The numbers end up almost as appalling.

For Egypt and Jordan, in fact, the percentage favoring the death penalty for apostasy was higher in the general population of Muslims than for the subpopulation of Muslims favoring sharia, albeit within the margin of error.

Old and wrong chart

Updated chart

Why do we believe this information helps explain why Muslims kill Muslims? First, because it shows the high premium many Muslims place on religious purity. Second, because the two dominant sects of Islam tend to regard each other as false versions of Islam, sometimes to the point of regarding the competing sect as apostate.